[test run details] Implement Test mode

[jorgeepc]

This PR implements the new Test mode for the Test Run Detail page.

Changes

• Changed the UI components related to the Test Run Detail page.
• New UI components.
• Renamed most of the components to use the new Test Spec term (instead of Assertion).

Fixes

• fixes #1072

Checklist

• [x] tested locally
• [ ] added new dependencies
• [ ] updated the docs
• [ ] added a test

Screenshots